There will be markers on a map, if a user clicks on the marker, they will see more information specific to the wine they select. We would probably need to be able to add custom fields to each wine/store for descriptions, images, etc.

Will Store locator plus work as a solution and if so what extensions would we need to be able to build this?

There are already fields to attach an image, description, etc. There are several extender add-ons that add more fields that may suit what you need. There is no “wine extender” add-on, so you may need custom fields for that. The other option is to use the Tagalong premium add-on to categorize locations such as stores that carry specific types of wine. Tagalong can also create parent/child categories so you can have types of wine sorted by region, type, character, etc. and allow people to sort/select by those attributes.

All of the attributes can be displayed in the info bubble on the map. Use Enhanced Map to control that layout and what data is displayed.